Regional oximetry sensor

ABSTRACT

A regional oximetry sensor has a sensor head attachable to a patient skin surface so as to transmit optical radiation into the skin and receive that optical radiation after attenuation by blood flow within the skin. The sensor includes windows that press into the skin to maximize optical transmission. A stem extending from the sensor head transmits electrical signals between the sensor head and an attached cable. In a peel resistant configuration, the stem is terminated interior to the sensor head and away from a sensor head edge so as to define feet along either side of the stem distal the stem termination. The stem interior termination transforms a peel load on a sensor head adhesive to less challenging tension and shear loads on the sensor head adhesive.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57. Thepresent application claims priority benefit under 35 U.S.C. §119(e) toU.S. Provisional Patent Application Ser. No. 62/012,170, filed Jun. 13,2014, titled Peel-Off Resistant Regional Oximetry Sensor, U.S.Provisional Patent Application Ser. No. 61/887,878 filed Oct. 7, 2013,titled Regional Oximetry Pod; U.S. Provisional Patent Application Ser.No. 61/887,856 filed Oct. 7, 2013, titled Regional Oximetry Sensor; andU.S. Provisional Patent Application Ser. No. 61/887,883 filed Oct. 7,2013, titled Regional Oximetry User Interface; all of theabove-referenced provisional patent applications are hereby incorporatedin their entireties by reference herein.

FIELD

The present disclosure relates to the field of optical basedphysiological sensors.

BACKGROUND

Regional oximetry, also referred to as tissue oximetry and cerebraloximetry, enables the continuous assessment of the oxygenation oftissue. The measurement is taken by placing one or more sensors on apatient, frequently on the patient's left and right forehead. Regionaloximetry estimates regional tissue oxygenation by transcutaneousmeasurement of areas that are vulnerable to changes in oxygen supply anddemand. Regional oximetry exploits the ability of light to penetratetissue and determine hemoglobin oxygenation according to the amount oflight absorbed by hemoglobin.

Regional oximetry differs from pulse oximetry in that tissue samplingrepresents primarily (70-75%) venous, and less (20-25%) arterial blood.The technique uses two photo-detectors with each light source, therebyallowing selective sampling of tissue beyond a specified depth beneaththe skin. Near-field photo-detection is subtracted from far-fieldphoto-detection to provide selective tissue oxygenation measurementbeyond a pre-defined depth. Moreover, regional oximetry monitoring doesnot depend upon pulsatile flow.

Regional oximetry is a useful patient monitoring technique to alertclinicians to dangerous clinical conditions. Changes in regionaloximetry have been shown to occur in the absence of changes in arterialsaturation or systemic hemodynamic parameters.

SUMMARY

The present disclosure provides a regional oximetry sensor. The regionaloximetry sensor includes, for example, a face tape layer and a base tapelayer adhesively attachable to a patient skin surface. The regionaloximetry sensor also includes at least one emitter configured totransmit optical radiation into the patient skin surface, a near-fielddetector configured to detect the optical radiation after attenuation bytissue of the patient and a far field detector also configured to detectthe optical radiation after attenuation by tissue of the patient. In anembodiment, the regional oximetry sensor also includes one or more focuselements associated with one or more of the emitter, the near-fielddetector and the far field detector. In an embodiment any or all of theemitter, near-field detector and far field detector can be provided witha focus element. The focus element improves optical transmissions bygently pushing into the skin and providing improved optical couplingwith the skin.

The focus element can include a half-dome shape or any three dimensionalshape that gently pushes into the skin to improve optical coupling. Thefocus element can also have a rectangular planar base in order toprovide a support structure for cooperating with the face tape layerand/or other portions of the regional oximetry sensor. In an embodiment,the focus element associated with the near-field detector is smallerthan the focus element associated with the far field detector. Forexample, the near field detector includes a square shape whereas the farfield detector includes a larger rectangular shape.

In an embodiment of the regional oximetry sensor, the regional oximetrysensor can have a face tape layer and a base tape layer adhesivelyattachable to a patient skin surface as discussed above. The sensor canalso have at least one emitter configured to transmit optical radiationinto the patient skin surface, a near-field detector configured todetect the optical radiation after attenuation by tissue of the patient,and a far field detector also configured to detect the optical radiationafter attenuation by tissue of the patient. In some embodiments, theface tape layer and the base tape layer include a plurality of notchesforming a plurality of cutouts. The plurality of cutouts can be formedin a portion of a periphery or across the entire periphery of the baseand face tape layers, for example. The cutouts are mechanicallydecoupled from each other. Due to the mechanical decoupling, the cutoutsallow for greater ease of patient movement of the measurement site. Thisreduces patient discomfort while wearing the regional sensor.

In an embodiment, a peel-off resistant regional oximetry sensor isdisclosed. The peel-off resistant regional oximetry sensor includes ahead attachable to a patient skin surface and configured to transmitoptical radiation into the skin and receive that optical radiation afterattenuation by blood flow within the skin and a stem extending from thesensor head and configured to transmit electrical signals between thesensor head and an attached cable. The stem is terminated interior tothe sensor head and away from an edge of the sensor head so as to definefeet along either side of the stem distal the stem termination.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings and following associated descriptions are provided toillustrate embodiments of the present disclosure and do not limit thescope of the claims. Corresponding numerals indicate correspondingparts, and the leading digit of each numbered item indicates the firstfigure in which an item is found.

FIG. 1 is a depiction of a patient monitoring system including regionaloximetry sensors and a processing and display unit.

FIGS. 2A-C are top and bottom perspective views and a connector-endview, respectively, of a regional oximetry sensor;

FIGS. 3A-C are top exploded, bottom partially-exploded and bottomassembled perspective views, respectively, of regional oximetry sensorhead, stem and shell assemblies;

FIG. 4 is a bottom plan view a sensor cable and sensor flex circuitinterconnection;

FIGS. 5A-H are a top plan view, top and bottom perspective views, firstside and first side cross-sectional views, second side and second sidecross-sectional views and a bottom view, respectively, of a near-fielddetector lens;

FIGS. 6A-H are a top plan view, top and bottom perspective views, firstside and first side cross-sectional views, second side and second sidecross-sectional views and a bottom view, respectively, of a far-fielddetector lens;

FIG. 7 is a cross-sectional view of a regional oximetry sensor attachedto a tissue site and corresponding near-field and far-fieldemitter-to-detector optical paths;

FIGS. 8A-B are a regional oximetry monitor display of sensor placementoptions for an adult and a child, respectively; and

FIG. 8C is an exemplar regional oximetry monitor display using tworegional sensors.

FIGS. 9A-B are top perspective views of a regional oximetry sensor beinginadvertently peeled from a skin-surface monitoring-site due to apulling force applied to the sensor stem and interconnecting sensorcable;

FIG. 10 is a top perspective view of a peel-off resistant regionaloximetry sensor;

FIGS. 11 A-B are top perspective views of a peel-off resistant regionaloximetry sensor adhering to a skin-surface monitoring site despite apulling force applied to the sensor stem and interconnecting sensorcable; and

FIGS. 12A, 12B, 13A and 13B are side-by-side, top perspective views of aregional oximetry sensor and a peel-off resistant regional oximetrysensor subjected to like pulling forces and the corresponding impact ofanti-peel feet extending from the cable-side of the peel-off resistantregional oximetry sensor.

DETAILED DESCRIPTION

Aspects of the disclosure will now be set forth in detail with respectto the figures and various embodiments. One of skill in the art willappreciate, however, that other embodiments and configurations of thedevices and methods disclosed herein will still fall within the scope ofthis disclosure even if not described in the same detail as some otherembodiments. Aspects of various embodiments discussed do not limit thescope of the disclosure herein, which is instead defined by the claimsfollowing this description.

FIG. 1 is a physiological monitoring system 100 configured to measureand display regional oximetry measurements. The physiological monitoringsystem 100 includes at least a display 103 and a processor (not shown)for processing and displaying physiological measurements. Thephysiological monitoring system 100 also includes at least one sensor200 for detecting physiological information and providing thatphysiological information to the processor of the physiologicalmonitoring system 100. In the embodiment of FIG. 1, the physiologicalmonitoring system includes a removable hand held physiological monitor105. The physiological monitoring system 100 of FIG. 1 also includes asensor cable system 106 that includes wiring 107 and a sensor connector109. Sensor connector 109 includes ports for two or more sensors. Thesensors are described in more detail with respect to FIGS. 2A-2C.

FIGS. 2A-C illustrate a regional oximetry sensor 200 embodiment having asensor head 210, stem 220, shell 230, cable 240 and connector 250. Thesensor head 210 houses an emitter 282, a near-field detector 284 and afar-field detector 288 within a layered tape having a top side 211 andan adhesive bottom side 212 disposed on a release liner 260. The releaseliner 260 is removed so as to adhere the bottom side 212 to a skinsurface. The sensor head 210 also includes notches or channels 291 thatform cutouts 293. The cutouts 293 are independently flexible from otherneighboring cutouts. Because of the various placement locations of thesensors on the human body and the movement forces placed on regionaloximetry sensors, the cutouts 293 allow the sensor head 210 to berelatively large to increase the measurement area and adhesive surfacearea without greatly inhibiting patient movement. Thus, for example,when a patient moves their forehead with a sensor 200 adhesivelyattached, the sensor allows for some movement of the underlying skin sothat the patient is more comfortable, yet provide a large enough surfacearea to provide good measurement and adhesive qualities.

The regional oximetry sensor 200 is substantially flat, allowing thesensor to adhere to the patient without significant bulges. The stem 220extends out radially outward from the sensor head 210. The stem ispositioned to extend from a radial edge in order to provide a clean exitfrom the body for wiring and cables. The radial placement also providesfor streamlined sensor construction and prevents unnecessary bending orwrapping of internal or external wires.

The emitter 282 and detectors 284, 288 have a lens that protrudes fromthe bottom side 212, advantageously providing a robust optics-skininterface. The top side 211 has emitter/detector indicators 272-278 soas to aid precise sensor placement on a patient site. The shell 230houses the stem 220 to cable 240 interconnect, described in detail withrespect to FIGS. 3A-C, below. The connector 250 is a 12-pin, D-shapedplug.

FIGS. 3A-C illustrate an assembly of a regional oximetry sensor portionincluding a head assembly (FIG. 3A) and a sensor cable to flex circuitinterconnect (FIGS. 3B-C). As shown in FIG. 3A, a sensor head assembly301 has a face tape 310, a flex circuit 320, a sensor cable 330, a stemtape 340, a base tape 350, a shell top 360 and a shell base 370. Theface tape 310 and base tape 350 encase the flex circuit 320 andcorresponding emitter and detectors. The shell top and base 360, 370encase the sensor cable 330 to flex circuit 320 interconnect, describedin further detail with respect to FIGS. 4A-B, below. The stem tape 340encases the flex circuit 320 below the base tape 350.

FIG. 4 illustrates sensor flex circuit 320 to sensor cable 330interconnection. The flex circuit 320 is positioned on mounting pins inthe top shell 360 (FIG. 3B). As shown in FIG. 4, cable 330 wires aresoldered to flex circuit pads 410, 420. Cable 330 Kevlar bundles arewrapped around a shell post 430 for strain relief and secured withadhesive. A detector shield flap 440 is folded over detector wiressoldered to the detector pads 410 and secured with Kapton tape. The baseshell 370 (FIG. 3B) is then glued in place over the top shell 360 (FIG.3B). In the embodiment of FIG. 4, the connections to the flex circuit320 include four emitter anode conductors controlling four differentwavelength emitters, a common emitter cathode conductor and an emittershield, two near-field detector conductors, two far-field detectorconductors and a detector shield. In an embodiment, the emitter anddetector connections are physically separated between different circuitpads, for example, pads 410 and 420. This reduces and/or prevents crosstalk and noise between the emitter lines and the detector lines. Ofcourse a person of skill in the art will understand from the presentdisclosures that different numbers and types of connectors can be usedwith the presently described connection system.

FIGS. 5A-H illustrate an emitter lens and a near-field detector lens 500having a generally half-dome focus element 501 and a generallyrectangular, planar base 502. As described above, the lens base 502 isdisposed over the flex-circuit-mounted emitter and near-field detectorin order to focus emitted and detected light. Also as described above,the lens focus element 501 is configured to gently press into a tissuesite when applied to the patient in order to maximize opticaltransmission via the skin surface. The focus elements can also usedifferent three dimensional shapes as well in order to improve opticalcoupling with the skin and the present disclosure is not limited to thespecific embodiments disclosed herein. For example, the lens can bespherical, cubed, rectangular, square, circular oblong or any othershape to increase optical transmission with the skin.

FIGS. 6A-H illustrate a far-field detector lens 600 having a generallyoblong, half-dome focus element 601 and a generally oblong, planar base602. As described above, the lens base 602 is disposed over theflex-circuit-mounted far-field detector so as focus detector receivedlight. Also as described above, the lens focus element 601 gentlypresses into a tissue site in order to maximize optical transmission viathe skin surface. Also, as described above with respect to FIG. 5, thepresent disclosure is not limited to the specific dimensions and shapedescribed herein which are provided for illustrative purposes. Rather,as discussed above, the present disclose extends to other shapes andsizes of a focus element that will improve optical coupling. Moreover,the focus element 601 can comprise two or more different focus elementsinstead of a single larger focus element.

FIG. 7 illustrates a regional oximetry sensor 700 attached to a tissuesite 70 so as to generate near-field 760 and far-field 770emitter-to-detector optical paths through the tissue site 70. Theresulting detector signals are processed so as to calculate and displayoxygen saturation (SpO₂), delta oxygen saturation (ΔSpO₂) and regionaloxygen saturation (rSO₂), as shown in FIG. 8C, below. The regionaloximetry sensor 700 has a flex circuit layer 710, a tape layer 720, anemitter 730, a near-field detector 740 and a far-field detector 750. Theemitter 730 and detectors 740, 750 are mechanically and electricallyconnected to the flex circuit 710. The tape layer 720 is disposed overand adheres to the flex circuit 710. Further, the tape layer 720attaches the sensor 700 to the skin 70 surface.

As shown in FIG. 7, the emitter 730 has a substrate 732 mechanically andelectrically connected to the flex circuit 710 and a lens 734 thatextends from the tape layer 720. Similarly, each detector 740, 750 has asubstrate 742, 752 and each has a lens 744, 754 that extends from thetape layer. In this manner, the lenses 734, 744, 754 press against theskin 70, advantageously increasing the optical transmission andreception of the emitter 730 and detectors 740, 750 through improvedoptical coupling. The lenses press into the skin and provide a moredirect angle of light propagation through the skin between the emitterand detectors.

FIGS. 8A-B illustrate regional oximetry monitor embodiments fordesignating adult and child sensor placement sites. As shown in FIG. 8A,an adult form 801 is generated on a user interface display. Between oneand four sensor sites can be designated on the adult form 801, includingleft and right forehead 810, forearm 820, chest 830, upper leg 840,upper calf 850 and calf 860 sites. Accordingly, between one and foursensors 200 (FIGS. 2A-C) can be located on these sites. A monitor incommunication with these sensors then displays between one and fourcorresponding regional oximetry graphs and readouts, as described withrespect to FIG. 8C, below. As illustrated in FIGS. 8A-8C, the sensor canbe positioned on a patient so that the sensor stem 220 and attachedcabling can extend radially out from the body on the various regionaloximetry sensor sites. This configuration reduces patient discomfort bypreventing wiring from crossing or crisscrossing over a patient face,torso or lower body. This configuration also reduces the potential forentanglement of wires from the multiple sensors and associated cabling.

As shown in FIG. 8B, a child form 802 is generated on a user interfacedisplay. Between one and four sensor sites can be designated on thechild form 802, including left and right forehead 810, left and rightrenal 870, and left and right abdomen 880 sites. Any number of regionaloximetry sensors can be deployed on a patient at the same time, butgenerally, between one and four sensors 200 (FIGS. 2A-C) are located onthese sites at a given time. A monitor in communication with thesesensors then displays between a corresponding regional oximetry graphsand readouts for each sensor, as described with respect to FIG. 8C,below. The displays of FIGS. 8A and 8B can also be selectively shownsuch that, for example, only an upper torso portion of the graphic isshown to prevent confusion by a care provider.

FIG. 8C illustrates a regional oximetry display 800 embodiment formonitoring parameters derived from between one and four regionaloximetry sensors 200 (FIGS. 2A-C). This particular example is a twosensor display for monitoring, for example, a forehead left 811 site anda forehead right 831 site. In an upper display portion, the foreheadleft 812 site displays, for example, an SpO₂ graph 812, an rSO₂ graph814 and an rSO₂ readout 816. Similarly, the forehead right 831 sitedisplays, for example, an SpO₂ graph 832, an rSO₂ graph 834 and an rSO₂readout 836.

Also shown in FIG. 8C, in a lower display portion, the forehead left 851site displays, for example, an SpO₂ readout 852, a ΔSO₂ readout 854 anda Δ_(base) readout 856. Similarly, the forehead right 830 site displays,for example, an SpO₂ readout 872, a ΔSO₂ readout 874 and a Δ_(base)readout 876.

FIGS. 9A-B illustrate a problem that arises with a regional oximetrysensor 200 during use. The connector 250 is fixedly connected to aphysiological monitor (not shown) that provides a read-out of parametersderived from the sensor 200. Patient movement away from the monitor mayoccur in a manner that pulls on the cable (not shown) and bends theattached stem 220 up and/or over the sensor head 210 (FIG. 9A).Continued patient movement away from the monitor may cause a portion ofthe sensor head 901 to peel off of the patient's skin (FIG. 2B),disrupting accurate parameter measurements. Indeed, continued patientmovement may completely dislodge the sensor head 210 from the patient.

A peel-off resistant regional oximetry sensor has a sensor headattachable to a patient skin surface so as to transmit optical radiationinto the skin and receive that optical radiation after attenuation byblood flow within the skin. A stem extending from the sensor headtransmits electrical signals between the sensor head and an attachedcable. The stem is terminated interior to the sensor head and away froma sensor head edge so as to define feet along either side of the stemdistal the stem termination. The stem interior termination substantiallytransforming a peel load on a sensor head adhesive to less challengingtension and shear loads on the sensor head adhesive.

FIG. 10 illustrates an advantageous peel-off resistant regional oximetrysensor 1000 embodiment having a sensor head 1010, stem 1020, shell 230,cable 240 and connector 250. The sensor head 1010 houses an emitter, anear-field detector and a far-field detector within a layered tapehaving a top side and an adhesive bottom side disposed on a releaseliner, similar to that described with respect to FIGS. 2A-B, above. Thepeel-off resistant regional oximetry sensor 1000 has peel-resistant feet1012 proximately disposed on either side of the stem. The feet aredefined by stem slots 1014 separating the feet from the stem. Thisconfiguration advantageously moves the stem 1020 base from the edge ofthe sensor head (e.g. 210 FIG. 2A) to the interior of the sensor head1010. As a result, potential peel loads on the sensor head adhesiveresulting from the stem 1020 being pulled over the sensor head aresubstantially reduced, as described with respect to FIGS. 12A-13B,below.

FIGS. 11A-B illustrate a peel-off resistant regional oximetry sensor1000 adhering to a skin-surface monitoring site despite a pulling forceapplied to the sensor stem 1020 and interconnecting sensor cable.Patient movement relative to connected monitor tends to cause the stem1020 to peel up the sensor head (see FIG. 2B, above). The sensor headfeet 1012, however, advantageously extend away from the point where thestem 1020 begins applying a load to the sensor head adhesive, thuscounteracting the peel away force. Further the resulting adhesive loadsare different in kind and magnitude than the adhesive loads on thesensor head shown and described with respect to FIG. 2, above.Comparative adhesive loads are described in detail with respect to FIGS.12A-13B, below.

FIGS. 12A-13B illustrate comparative adhesive loads applied to aregional oximetry sensor and a peel-off resistant regional oximetrysensor resulting from cable forces applied to the sensor head stems 220(FIGS. 12A-B), 1020 (FIGS. 13A-B). As shown in FIGS. 12A-B, the stem 220applies a substantial peel load 221 to the sensor head 210 adhesive 222,and the peel load 221 is distributed over a relatively small area 223 ofthe sensor head 210. It is well-know that a peel load 221 is asubstantial challenge to any adhesive, and the milder adhesives used onskin cannot easily overcome this challenge. As such, it is relativelyeasy for the sensor head 210 to become dislodged or completely detachedfrom the patient.

As shown in FIGS. 13A-B, the stem 1020 applies different loads 1021 tothe sensor head 310 adhesive 322, 323, 324 than described with respectto FIGS. 12A-B. In particular, there is a marginal peel load on theadhesive as the result of the adhesive feet 1012 positioned opposite theconnection point of the stem 1020 to the sensor head 1010. The sheerload due to the stem force 1021 is much less challenging to the feetadhesive 1024 compared to a peel load. Likewise, the tension load due tothe stem force 1021 is less challenging to the feet adhesive 1022, 1023,compared to a peel load, and that tension load is distributed on bothsides of the stem-to-head connection point. That is, the cumulativeeffect of positioning the stem 1020 somewhat to the interior of thesensor head 1010 and behind the feet 1021 is a greatly diminishedadhesive peel load and much less challenging shear and tension loadsdistributed over a larger adhesive footprint. The advantageous result isa sensor head-to-cable stem interface that is much less likely todislodge the sensor head from the patient when forces are applied to thesensor cable. Further, more skin-friendly adhesives can be utilized forsensor head attachment as a result of lowered adhesive loads.

A peel-off resistant regional oximetry sensor has been disclosed indetail in connection with various embodiments. These embodiments aredisclosed by way of examples only and are not to limit the scope of thisdisclosure or the claims that follow. One of ordinary skill in art willappreciate many variations and modifications.

Terminology

Embodiments have been described in connection with the accompanyingdrawings. However, it should be understood that the figures are notdrawn to scale. Distances, angles, etc. are merely illustrative and donot necessarily bear an exact relationship to actual dimensions andlayout of the devices illustrated. In addition, the foregoingembodiments have been described at a level of detail to allow one ofordinary skill in the art to make and use the devices, systems, etc.described herein. A wide variety of variation is possible. Components,elements, and/or steps can be altered, added, removed, or rearranged.While certain embodiments have been explicitly described, otherembodiments will become apparent to those of ordinary skill in the artbased on this disclosure.

Conditional language used herein, such as, among others, “can,” “could,”“might,” “may,” “e.g.,” and the like, unless specifically statedotherwise, or otherwise understood within the context as used, isgenerally intended to convey that certain embodiments include, whileother embodiments do not include, certain features, elements and/orstates. Thus, such conditional language is not generally intended toimply that features, elements and/or states are in any way required forone or more embodiments or that one or more embodiments necessarilyinclude logic for deciding, with or without author input or prompting,whether these features, elements and/or states are included or are to beperformed in any particular embodiment.

Depending on the embodiment, certain acts, events, or functions of anyof the methods described herein can be performed in a differentsequence, can be added, merged, or left out altogether (e.g., not alldescribed acts or events are necessary for the practice of the method).Moreover, in certain embodiments, acts or events can be performedconcurrently, e.g., through multi-threaded processing, interruptprocessing, or multiple processors or processor cores, rather thansequentially.

The various illustrative logical blocks, engines, modules, circuits, andalgorithm steps described in connection with the embodiments disclosedherein can be implemented as electronic hardware, computer software, orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. The described functionalitycan be implemented in varying ways for each particular application, butsuch implementation decisions should not be interpreted as causing adeparture from the scope of the disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the embodiments disclosed herein can be implementedor performed with a general purpose processor, a digital signalprocessor (DSP), an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor can be a microprocessor, but in thealternative, the processor can be any conventional processor,controller, microcontroller, or state machine. A processor can also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The blocks of the methods and algorithms described in connection withthe embodiments disclosed herein can be embodied directly in hardware,in a software module executed by a processor, or in a combination of thetwo. A software module can reside in RAM memory, flash memory, ROMmemory, EPROM memory, EEPROM memory, registers, a hard disk, a removabledisk, a CD-ROM, or any other form of computer-readable storage mediumknown in the art. An exemplary storage medium is coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium can beintegral to the processor. The processor and the storage medium canreside in an ASIC. The ASIC can reside in a user terminal. In thealternative, the processor and the storage medium can reside as discretecomponents in a user terminal.

While the above detailed description has shown, described, and pointedout novel features as applied to various embodiments, it will beunderstood that various omissions, substitutions, and changes in theform and details of the devices or algorithms illustrated can be madewithout departing from the spirit of the disclosure. As will berecognized, certain embodiments of the inventions described herein canbe embodied within a form that does not provide all of the features andbenefits set forth herein, as some features can be used or practicedseparately from others. The scope of certain inventions disclosed hereinis indicated by the appended claims rather than by the foregoingdescription. All changes which come within the meaning and range ofequivalency of the claims are to be embraced within their scope.

What is claimed is:
 1. A regional oximetry sensor comprising: a facetape layer; a base tape layer adhesively attachable to a patient skinsurface; at least one emitter configured to transmit optical radiationinto the patient skin surface; a near-field detector configured todetect the optical radiation after attenuation by tissue of the patient;a far field detector also configured to detect the optical radiationafter attenuation by tissue of the patient; and at least one focuselement associated with at least one of the at least one emitter, thenear-field detector and the far field detector.
 2. The regional oximetrysensor of claim 1, wherein the focus element comprises a half-domeshape.
 3. The regional oximetry sensor of claim 2, wherein the focuselement comprises a rectangular planar base.
 4. The regional oximetrysensor of claim 1, wherein the focus element comprises a threedimensional shape that allows the focus element to press into thepatient skin surface.
 5. The regional oximetry sensor of claim 1,wherein the focus element increases optical transmission with thepatient skin surface.
 6. The regional oximetry sensor of claim 1,further comprising at least a second focus element.
 7. The regionaloximetry sensor of claim 6, wherein at least one focus element isassociated with the near-field detector and at least one focus elementis associated with the far field detector.
 8. The regional oximetrysensor of claim 7, wherein the focus element associated with the nearfield detector is smaller than the focus element associated with the farfield detector.
 9. The regional oximetry sensor of claim 6, furthercomprising a third focus element associated with the at least oneemitter.
 10. A regional oximetry sensor comprising: a face tape layer; abase tape layer adhesively attachable to a patient skin surface; atleast one emitter configured to transmit optical radiation in to thepatient skin surface; a near-field detector configured to detect theoptical radiation after attenuation by tissue of the patient; a farfield detector also configured to detect the optical radiation afterattenuation by tissue of the patient; and wherein the face tape layerand the base tape layer cooperate together and include a plurality ofnotches forming a plurality of cutouts.
 11. The regional oximetry sensorof claim 10, wherein the plurality of notches forming the plurality ofcutouts are formed on a periphery of the base and face tape layers. 12.The regional oximetry sensor of claim 11, wherein the cutouts aremechanically decoupled from each other.
 13. The regional oximetry sensorof claim 12, wherein the cutouts allow for ease of patient movement ofthe measurement site.
 14. A peel-off resistant regional oximetry sensorcomprising: a sensor head attachable to a patient skin surface andconfigured to transmit optical radiation into the skin and receive thatoptical radiation after attenuation by blood flow within the skin; and astem extending from the sensor head and configured to transmitelectrical signals between the sensor head and an attached cable;wherein the stem is terminated interior to the sensor head and away froman edge of the sensor head so as to define feet along either side of thestem distal the stem termination.
 15. The regional oximetry sensor ofclaim 14, wherein the sensor head and stem form a single continuousbody.
 16. The regional oximetry sensor of claim 14, wherein the sensorhead and stem are substantially flat.
 17. The regional oximetry sensorof claim 14, wherein the stem extends radially outward from the sensorhead.
 18. A peel-off resistant regional oximetry sensor comprising: aface tape layer; a base tape layer adhesively attachable to a patientskin surface, the face tape layer and base tape layer cooperating toform a sensor head and stem, the sensor head including notches on eitherside of the stem at the junction of the sensor head and stem, thenotches mechanically decoupling the sensor stem from a radial edge ofthe sensor head; at least one emitter configured to transmit opticalradiation in to the patient skin surface; a near-field detectorconfigured to detect the optical radiation after attenuation by tissueof the patient; and a far field detector also configured to detect theoptical radiation after attenuation by tissue of the patient.
 19. Theregional oximetry sensor of claim 18, wherein the sensor head and stemform a single continuous body.
 20. The regional oximetry sensor of claim18, wherein the sensor head and stem are substantially flat.
 21. Theregional oximetry sensor of claim 18, wherein the stem extends radiallyoutward from a distal portion of the sensor head.